u_chb1ap.m

来自「很多matlab的源代码」· M 代码 · 共 20 行

function [b,a] = u_chb1ap(N,Rp,Omegac)
% Unnormalized Chebyshev-1 Analog Lowpass Filter Prototype
% ----------------------------------------------------------
% [b,a] = u_chb1ap(N,Rp,Omegac)
% b = numerator polynomial coefficients
% a = denominator polynomial coeffients
% N = Order of the Elliptic Filter
% Rp = Passband Ripple in dB ; Rp>0
% Omegac = Cutoff frequency in radians/sec
% 
[z,p,k] = cheb1ap(N,Rp)
a = real(poly(p));
aNn = a(N+1);
p = p*Omegac;
a = real(poly(p));
aNu = a(N+1);
k = k*aNu/aNn;
b0 = k;
B = real(poly(z));
b = k*B;